1. Field of Invention
The present invention relates to an LED driving circuit. More particularly, the present invention relates to an LED driving circuit having an enable pin with multi-function.
2. Description of Related Art
For a conventional LED driving integrated circuit (IC) chip, it usually has an enable (EN) pin used for receiving a dimming control signal for controlling current flowing into LEDs. The dimming of LEDs is often performed within the frequency range of 2-20 KHz. However, if dimming of LEDs is performed over the frequency range of 2-20 KHz, and for example, within the frequency range of 20-200 KHz, the LED driving chip cannot correspondingly operate in accordance with the dimming control signal. Thus, the LED driving chip could malfunction due to its high-frequency dimming operation.